================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_ready_cb+0xd6/0x160 net/bluetooth/l2cap_sock.c:1705 Read of size 8 at addr ffff888057ad6188 by task kworker/u9:0/12334 CPU: 1 UID: 0 PID: 12334 Comm: kworker/u9:0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: hci4 hci_rx_work Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 l2cap_sock_ready_cb+0xd6/0x160 net/bluetooth/l2cap_sock.c:1705 l2cap_le_start+0x251/0x11e0 net/bluetooth/l2cap_core.c:1368 l2cap_conn_ready net/bluetooth/l2cap_core.c:1621 [inline] l2cap_connect_cfm+0x83d/0x1390 net/bluetooth/l2cap_core.c:7352 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2139 le_conn_complete_evt+0xf65/0x1430 net/bluetooth/hci_event.c:5847 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5873 hci_event_func net/bluetooth/hci_event.c:7781 [inline] hci_event_packet+0x7af/0x12c0 net/bluetooth/hci_event.c:7838 hci_rx_work+0x3ee/0x1040 net/bluetooth/hci_core.c:4077 process_one_work+0x949/0x1650 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0xb46/0x1140 kernel/workqueue.c:3443 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 18942: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5219 [inline] __kmalloc_noprof+0x35c/0x760 mm/slub.c:5231 kmalloc_noprof include/linux/slab.h:966 [inline] sk_prot_alloc+0xe7/0x210 net/core/sock.c:2245 sk_alloc+0x3a/0x390 net/core/sock.c:2301 bt_sock_alloc+0x3b/0x310 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1916 [inline] l2cap_sock_create+0x147/0x330 net/bluetooth/l2cap_sock.c:1958 bt_sock_create+0x163/0x240 net/bluetooth/af_bluetooth.c:135 __sock_create+0x4e3/0x960 net/socket.c:1620 sock_create net/socket.c:1678 [inline] __sys_socket_create net/socket.c:1715 [inline] __sys_socket+0xd9/0x310 net/socket.c:1762 __do_sys_socket net/socket.c:1776 [inline] __se_sys_socket net/socket.c:1774 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1774 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 18942: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2687 [inline] slab_free mm/slub.c:6124 [inline] kfree+0x1c1/0x630 mm/slub.c:6442 sk_prot_free net/core/sock.c:2284 [inline] __sk_destruct+0x623/0x880 net/core/sock.c:2384 l2cap_sock_release+0x192/0x230 net/bluetooth/l2cap_sock.c:1456 __sock_release+0xb9/0x250 net/socket.c:666 sock_close+0x1c/0x30 net/socket.c:1470 __fput+0x44f/0xa70 fs/file_table.c:469 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888057ad6000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 392 bytes inside of freed 2048-byte region [ffff888057ad6000, ffff888057ad6800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888057ad1000 pfn:0x57ad0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801b042000 ffffea0001591010 ffffea00015d2c10 raw: ffff888057ad1000 0000000000080007 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b042000 ffffea0001591010 ffffea00015d2c10 head: ffff888057ad1000 0000000000080007 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea00015eb401 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5824, tgid 5824 (syz-executor), ts 85264525315, free_ts 31192661204 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2485 alloc_slab_page mm/slub.c:3253 [inline] allocate_slab+0x83/0x660 mm/slub.c:3444 new_slab mm/slub.c:3502 [inline] ___slab_alloc+0x150/0x6b0 mm/slub.c:4376 __slab_alloc_node mm/slub.c:4442 [inline] slab_alloc_node mm/slub.c:4818 [inline] __do_kmalloc_node mm/slub.c:5218 [inline] __kmalloc_node_track_caller_noprof+0x304/0x7b0 mm/slub.c:5327 kmalloc_reserve net/core/skbuff.c:635 [inline] pskb_expand_head+0x228/0x1320 net/core/skbuff.c:2315 netlink_trim+0x1b3/0x2c0 net/netlink/af_netlink.c:1299 netlink_broadcast_filtered+0xd6/0x1020 net/netlink/af_netlink.c:1512 nlmsg_multicast_filtered include/net/netlink.h:1165 [inline] nlmsg_multicast include/net/netlink.h:1184 [inline] nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2593 __dev_notify_flags+0xf2/0x310 net/core/dev.c:9782 rtnl_configure_link net/core/rtnetlink.c:3606 [inline] rtnl_newlink_create+0x657/0xb70 net/core/rtnetlink.c:3850 __rtnl_newlink net/core/rtnetlink.c:3957 [inline] rtnl_newlink+0x1666/0x1be0 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978 __free_pages mm/page_alloc.c:5369 [inline] free_contig_range+0xbb/0x170 mm/page_alloc.c:7373 destroy_args+0x4e5/0x570 mm/debug_vm_pgtable.c:993 debug_vm_pgtable+0x3f8/0x410 mm/debug_vm_pgtable.c:1368 do_one_initcall+0x250/0x8d0 init/main.c:1382 do_initcall_level+0x104/0x190 init/main.c:1444 do_initcalls+0x59/0xa0 init/main.c:1460 kernel_init_freeable+0x2a6/0x3e0 init/main.c:1692 kernel_init+0x1d/0x1d0 init/main.c:1582 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888057ad6080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888057ad6100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888057ad6180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888057ad6200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888057ad6280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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